The fire started around 11 a.m. inside the Wells Street home, located between Grand Traverse and Euston streets, and quickly spread throughout the small structure. Flames could be seen coming through a front window as firefighters made their way through heavy smoke.

Doug Halstead, Burton Fire Chief, said there are a number of investigators sifting through the rubble, including a state fire marshal, but no cause has been determined. The woman's name and age have not been released.

Halstead said the fire was “very involved” and described the investigation as a “slow, meticulous process,” with officials looking for clues as to what started the fire as small as a bead on the end of a copper wire.

“There’s a lot of stuff to go through,” he said. Halstead does not believe the fire was arson.

Neighbors from the area stood outside to watch the fire, as more than a dozen firefighters worked to put out the flames and smoke. Resident Bob Ostrander lives across the street and said he "saw flames shooting out the door."